upd77c25

The NEC uPD77C25 as Nintendo shipped it across four microcodes. The DSP-2 is modelled with its commands proved rather than sampled: the tile conversion exhaustively over all 256 bits, the merge over every input it accepts, and the whole chip differentially against a reference validated on 71,970,987 recorded bytes.

NEC uPD7725 and uPD96050 DSP emulator in Python, cycle accurate. Held to NEC's data book for every flag each ALU operation touches and to a per-encoding corpus for the whole processor state: 1,002,240 instructions compared, zero disagreements. 100% branch coverage, no firmware ever